With a greater appreciation as to environmental damage associated with pesticide usage, there are ever-increasing limitations as to the classes of chemical compounds suitable as pesticides as well as limitations when those pesticides can be spread on a crop. In many cases in order to ameliorate environmental damage associated with pesticide application, pesticide use is mandated during seasons when the pest lifecycle is not at the most vulnerable stage. With integrated pest management now endorsed by environmental regulatory agencies, industry associations, and entomologists, more judicious pesticide usage should be expected in the future.
An ongoing problem in minimizing pesticide usage is the difficulty in delivery of a pesticide efficiently to a target plant within a large area of cultivated vegetation. A practical labor-saving approach to pesticide delivery to such as golf courses, parks, lawns, gardens and agricultural fields has been broadcast application of granular products containing a pesticide with equipment such as a rotary spreader. Using granular products having particle sizes in the range of about 1 millimeter to about 10 millimeters, an operator can cover a large area with minimal distance traversed by the spreader itself while at the same time applying the granular pesticide with relative uniformity over the desired area. Unfortunately, such granular pesticides often remain in solid or semisolid form for a considerable time following application. Since the pesticide is typically bound physically within the granule, the pesticide efficacy is reduced or delayed, potentially resulting in a loss of active ingredient via volatilization or photodegradation.
A further consequence of granular pesticide distribution is that the granules are subject to removal by plant culture operations such as mowing or aerating, or environmental factors such as wind and rain. Unintended removal is especially problematic on sloping ground where the underlying soils have low percolation rates, where ground cover is sparse, or in areas of high foot traffic. These actions contribute to a loss of uniformity in pesticide application and therefore efficacy is altered due to excessive concentration of the product within certain treated areas while other areas suffer diminished pesticide concentrations. Additionally, a long-persistent granule creates a greater likelihood that people, beneficial insects, and animals will come into physical contact with the granules, resulting in undue adverse health effects and environmental degradation. An alternative to long-persistent granule products is spray application of a liquid pesticide. Unfortunately, spray treatments require considerable skill for application and result only in contact to exposed foliage with other surfaces receiving only indirect drainage from exposed foliage. Additionally, spray treatment tends to dissipate quickly. Due to spray atomization of liquid pesticides, a considerable amount of pesticide is lost through volatilization and wind drift and tends to be applied in greater quantities to reach pests dwelling on the underside of foliage. The net result is inefficient pesticide usage; non-target hazard effects to: people, wildlife, and non-target property. Other deleterious effects of inefficient usage of pesticides include leaching through rain contact causing environmental wastewater management issues and aerosol pollution.
Thus, there exists a need for a pesticide delivery granule that affords rapid release from a solid pesticide granule and efficient delivery of a complementary liquid pesticide.